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Bayley Scales of Infant and Toddler Development- Fourth Edition

The Bayley Scales of Infant and Toddler Development –Fourth Edition (Bayley-4; Bayley & Aylward, 2019) may be used to identify developmental delays, chart a child’s progress, and teach parents about the child’s development. This updated version will be published in September 2019.

Available from Pearson


The Bayley Scales of Infant and Toddler Development –Fourth Edition (Bayley-4; Bayley & Aylward, 2019) is an individually-administered, norm-referenced instrument that can be used to identify developmental delays, monitor progress, and teach parents about children’s development. The test is designed to be used with children ages 16 days to 42 months. It consists of five scales: Cognitive (visual preference, attention, memory, sensorimotor, exploration and manipulation, concept formation), Language (receptive and expressive), Motor (fine and gross), Social-Emotional (communicating needs, self-regulation using emotional signals), and Adaptive Behavior (listening and understanding, talking, caring for self, relating to others, playing). It also includes a test observations measure to aid in intervention planning. This edition also saves significant time through shortened adaptive behavior content from the Vineland 3. Web-based administration, scoring, and reporting via Q-global is available.


Age: 16 days to 42 months

Time to Administer: 30-70 minutes (depending on on child’s age)

Method of Administration: Individually-administered, norm-referenced instrument with play-based format for Cognitive, Language, annd Motor Scales; caregiver questionnaire for Social-Emotional and Adaptive Functioning.
Yields standard scores, percentile ranks with cut-scores, confidence intervals, T-scores, growth and developmental age scores.

Subscales: Composite Scores: Language, Motor, Adaptive Behavior (General Adaptive Composite); Composite score equivalents available for Cognitive and Social-Emotional
Subscale Scores: Cognitive; Receptive Language; Expressive Language; Fine Motor; Gross Motor

Autism Related Research

The research detailed below is specific to the previously published version, the Bayley-III.

Torras-Mana et al. (2016)

Age Range: Time 1, average age 36 months; Time 2, average age 48-54 months

Sample Size: 135

Topics Addressed:

Utility of the Bayley-III in early assessment of cognitive and language functions among children with ASD

Outcome:Torras-Mana et al. (2016)

Lower scores on the cognitive and language Bayley-III scales before 3.5 years of age predicted lower cognitive and oral language levels at 4 years of age. A significant correlation was found between the Cognitive Bayley-III Scale and the General Cognitive score on the McCarthy Scales of Children’s Abilities, and with the K-ABC Mental Processing score. An association between the non-verbal cognitive level and oral language level acquired at 4 years of age was found.

Conclusion: the Bayley-III Spanish translation is a useful instrument in cognitive and language assessment of ASD, which is consistent with findings from studies conducted by the test developer with the English language version.

Long, Gurka, & Blackman (2011)

Age Range: 16-38 months

Sample Size: 147

Topics Addressed:

Compare performance of children with ASD to typically developing peers on Bayley-III

Outcome:Long, Gurka, & Blackman (2011)

While language skills in children with ASD were more significantly delayed than language skills in children without ASD, there was less discrepancy in the cognitive skills of children with and without ASD.

Conclusion: the Bayley-III was useful for measuring cognitive skills of young children with ASD.